World environmental experts are warning that billions of people across the world could soon face increased risks of flooding and shortages of food and water as global warming takes effect.

The bleak conclusion came ahead of the publication of a key report by hundreds of international environmental experts in Brussels, Belgium.

According to a report from the British Broadcasting Corporation, people living in poverty willbe worst affected.

The report states that the observed increase in global average temperature is likely due to man-made greenhouse gas emissions.

The scientific work reviewed by Intergovern-mental Panel on Climate Change (IPCC) scientists, includes more than 29,000 pieces of data on observed changes in physical and biological aspects of the natural world.

Eighty-nine per cent of these, it believes, are consistent with a warming world.

Warming world

"This (the report) further underlines both how urgent it is to reach a global agreement on reducing greenhouse gas emissions and how important it is for us all to adapt to the climate change that is already under way," European Environment Commissioner, Stavros Dimas, told the Reuters news agency.

A summary of the report will be sent to world leaders in time for a G8 summit of industrialised nations in June.

It is the second in a series of IPCC reports coming out this year, together making up its fourth global climate assessment.

The first element, on the science of climate change, released in February, concluded that it was at least 90 per cent likely that human activities are principally responsible for the warming observed since 1950.

The third part, due in May, will focus on ways of curbing the rise in greenhouse gas concentrations and temperature.

A fourth report in November will sum up all the findings.

The key findings of the report